Merge pull request #65 from jkuczm/cbv

Replacement of remaining function based views with class based equivalents.
Change activate_url in test for update activation

In test_update_request_activate subscription activation was tested
instead of update activation.
Change submit input value in subscription_update

Form submit input in subscription_update.html template had "Subscribe"
in value attribute, change it to "Update subscription".
Merge pull request #72 from jkuczm/fix_test_update_request_activate

Fix activate_url in test for update activation.
Merge pull request #73 from jkuczm/fix_subscription_update_template

Change submit input value in subscription_update
Updated e-mail address
Updated source strings.
Fix JavaScript submitlink on "Add submission"

Template admin/newsletter/submission/change_form.htm always tried to add
some JavaScript event for submitlink, even on "Add submission" page
where there's no submitlink.

Fixed by porting submit_interface.js to jQuery.